On November 26, 1997, the M/V Kuroshima was anchored near Unalaska, Alaska when extreme weather conditions dislodged it from its anchorage. Winds exceeding 90 miles per hour and waves exceeding 25 feet forced the vessel onto rocks, where its hull was punctured. Approximately 39,000 gallons of heavy fuel oil (IFO 380) were discharged into marine waters, onto adjacent shorelines, into a creek, and into Summer Bay Lake. Shoreline cleanup was implemented immediately following the spill, but was suspended until spring due to harsh weather conditions, safety concerns, and inefficient cleanup operations. Because the oil had a very high viscosity, was stranded high on the shoreline and winter had set in, the oil did not present an immediate environmental or human health threat. It was suspected that some of the discharged oil mixed with sand as it moved through the surf zone and sank when it entered the lake. During the winter, state and federal agencies and the responsible party developed a plan to survey the lake and creek for submerged oil. In early spring, divers conducted visual surveys of the lake bottom along 6.5 miles of transect to locate submerged oil. Transect locations were identified using a Differential Global Positioning System and the bottom was videotaped. A survey approach similar to that used to conduct a shoreline cleanup assessment was employed to characterize the lake bottom and the nature and spatial extent of the submerged oil. An oil recovery plan and cleanup criteria were developed and implemented. This case study describes the approach and technology utilized to survey for submerged oil and presents the survey findings and oil recovery and disposal methods employed. The challenges presented by the remote location, difficult working conditions, and natural resource concerns are also discussed.

This content is only available as a PDF.